Ultrasound in the assessment of musculoskeletal involvement in systemic lupus erythematosus: state of the art and perspectives.

Musculoskeletal manifestations are extremely common in patients with systemic lupus erythematosus. Transient and migratory arthralgia is frequently reported even without clinical signs of joint or tendon inflammation. In less than 15% of patients, joints may be more severely affected by deforming (Jaccoud's arthropathy) and/or erosive arthropathy (Rhupus syndrome). In recent years, ultrasound has emerged as a promising imaging technique for the assessment of musculoskeletal involvement in systemic lupus erythematosus, having demonstrated the ability to detect inflammation and structural damage both at articular and periarticular level. Recent ultrasound studies have also revealed new insights into musculoskeletal involvement in patients with systemic lupus erythematosus, some of them questioning the traditional concepts of systemic lupus erythematosus arthropathy, with potential clinical, prognostic and therapeutic implications. In daily clinical practice, the use of ultrasound in the assessment of joint and tendon involvement in patients with systemic lupus erythematosus is still limited. Several methodological issues encountered in ultrasound studies evaluating musculoskeletal involvement in systemic lupus erythematosus patients need to be addressed in order to improve both the reliability and clinical usefulness of ultrasound findings. This paper reviews ultrasound studies assessing musculoskeletal involvement in patients with systemic lupus erythematosus, highlighting certainty, limits, potential applications and future perspectives of ultrasound use in systemic lupus erythematosus patients.

An anaesthetic pre-operative assessment clinic reduces pre-operative inpatient stay in patients requiring major vascular surgery.

BACKGROUND: Patients undergoing major vascular surgery (MVS) require extensive anaesthetic assessment. This can require extended pre-operative stays. AIMS: We investigated whether a newly established anaesthetic pre-operative assessment clinic (PAC) would reduce the pre-operative inpatient stay, avoid unnecessary investigations and facilitate day before surgery (DBS) admissions for patients undergoing MVS. PATIENT AND METHODS: One year following and preceding the establishment of the PAC the records of patients undergoing open or endovascular aortic aneurysm repair, carotid endarterectomy and infra-inguinal bypass were reviewed to measure pre-operative length of stay (LoS). RESULTS: Pre-operative LoS was significantly reduced in the study period (1.85 vs. 4.2 days, respectively, P < 0.0001). Only 12 out of 61 patients in 2007 were admitted on the DBS and this increased to 33 out of 63 patients (P = 0.0002). No procedure was cancelled for medical reasons. CONCLUSION: The PAC has facilitated accurate outpatient anaesthetic assessment for patients requiring MVS. The pre-operative in-patient stay has been significantly reduced.

Efficacy of fibrinolysis in the emergency department for acute myocardial infarction.

BACKGROUND: Patients with an acute myocardial infarction require a rapid response to their symptoms and the earlier fibrinolysis is given (where indicated), the better the outcome. AIMS: The aim of this study is to compare 'door to needle times' for fibrinolysis in Acute Myocardial Infarction (AMI) in three phases of one year each, at Letterkenny General Hospital. METHODS: In the PREINTERVENTION year all fibrinolysis was performed in the Coronary Care Unit (CCU). In the INTERVENTION year Emergency Department (ED) fast track fibrinolysis was introduced and in the POST INTERVENTION year most fibrinolysis was performed on fast track in the ED. RESULTS: The time saved by the introduction of ED fibrinolysis was significant, 41 minutes on average per patient. Elderly, female patients were more likely to bypass ED fast track fibrinolysis and to be brought to CCU for fibrinolysis, with attendant delays. This has educational implications in relation to the variation in clinical presentation of AMI with age and sex. CONCLUSION: The ED fast track fibrinolysis system is recommended as an effective, safe, achievable and worthwhile intervention towards improving 'door to needle times' for fibrinolysis in AMI.

Assessment of a simple artificial neural network for predicting residual neuromuscular block.

BACKGROUND: Postoperative residual curarization (PORC) after surgery is common and its detection has a high error rate. Artificial neural networks are being used increasingly to examine complex data. We hypothesized that a neural network would enhance prediction of PORC. METHODS: In 40 previously reported patients, neuromuscular function, neuromuscular block/antagonist usage and time intervals were recorded throughout anaesthesia until tracheal extubation by an observer uninvolved in patient care. PORC was defined as significant 'fade' (train of four <0.7) at extubation. Neuromuscular function was classified as PORC (value=1) or no PORC (value=0). A back-propagation neural network was trained to assign similar values (0, 1) for prediction of PORC, by examining the impact of (i) the degree of spontaneous recovery at reversal, and (ii) the time since pharmacological reversal, using the jackknife method. Successful prediction was defined as attainment of a predicted value within 0.2 of the target value. RESULTS: Twenty-six patients (65%) had PORC at tracheal extubation. Clinical detection of PORC had a sensitivity of 0 and specificity of 1, with an indeterminate positive predictive value and a negative predictive value of 0.35. Using the artificial neural network, one patient with residual block and one with adequate neuromuscular function were incorrectly classified during the test phase, with no indeterminate predictions, giving an artificial neural network sensitivity of 0.96 (chi(2)=44, P<0.001) and specificity of 0.92 (P=1), with a positive predictive value of 0.96 and a negative predictive value of 0.93 (chi(2)=12, P<0.001). CONCLUSIONS: Neural network-based prediction, using readily available clinical measurements, is significantly better than human judgement in predicting recovery of neuromuscular function.

Atracurium is associated with postoperative residual curarization.

BACKGROUND: Residual paralysis following the use of neuromuscular blocking drugs remains a clinical problem. As part of departmental quality assurance, we examined the degree of postoperative residual curarization (PORC) following atracurium. METHODS: Forty patients undergoing general anaesthesia involving atracurium were studied. Quantitative neuromuscular monitoring (mechanomyography, Myograph 2000, Biometer, Denmark) was performed by assessing the response to supramaximal train-of-four (TOF) stimulation of the ulnar nerve. Anaesthesia was provided by non-participating clinicians who were blinded to the study data. A TOF ratio

Gastroesophageal reflux during spontaneous respiration with the laryngeal mask airway.

PURPOSE: To determine the incidence of gastroesophageal reflux during general anesthesia with the Laryngeal Mask Airway (LMA). METHODS: Twenty unpremedicated patients with no risk factors for reflux having day case anesthesia were included. Type of surgery was Orthopedic (n=8), General (n=7) and Gynecological (n=5). The average duration of anesthesia was 38.1 min, range 12 - 71 min. Anesthesia was induced with 1-2 microg x kg(-1) fentanyl and 2-3 mg x kg(-1) propofol and maintained with oxygen 33%, nitrous oxide 66% and isoflurane 1% (end-tidal). Ventilation by hand was performed until spontaneous respiration resumed. To facilitate surgery, 13 patients were placed in the supine and seven in the lithotomy positions. Two pH-sensitive electrodes were used to identify reflux. One was placed in the oesophagus 20 cm from the anterior nares to detect esophageal reflux and the other was placed through the bars of the LMA to detect refluxing material around the LMA. RESULTS: Esophageal reflux occurred in 12 patients (60%), in five of the 13 in the supine position and in all patients in the lithotomy position. The LMA electrode detected a decrease in pH in four cases (20%), all in the lithotomy position. The incidence reflux in the lithotomy and supine positions was different (Exact Probability test; P = 0.01). CONCLUSION: This study suggests that the lithotomy position predisposes patients to a higher risk of aspiration than the supine position when using a LMA.

Preoperative education and outcome of patient controlled analgesia.

PURPOSE: To determine the effect of intensive preoperative education on the outcome of Patient Controlled Analgesia (PCA) postoperatively. METHODS: This prospective randomised study was carried out in a single teaching hospital over three months. One group of patients (n = 42) received a 20 min standardised tutorial regarding PCA use from a single investigator and the other group (n = 43) received no additional education apart from the routine preoperative anaesthetic consultation. A blinded investigator assessed the patients following surgery. Pain scores and morphine consumption, patient satisfaction, side-effect profile and anti-emetic use were recorded at six, 24 and 48 hr postoperatively. RESULTS: Pain scores, satisfaction scores and morphine consumption were similar in both groups throughout the study period. Fewer patients in the tutored group complained of nausea from 6 to 24 hr than did untutored patients (28% vs 51%; P < 0.05). More tutored patients used antiemetic medication from 0 to 6 (28% vs 12%; P < 0.05) and 6 to 24 hr (37% vs 19%; P < 0.05). Side effect profile and requirement for rescue analgesia was otherwise similar in both groups. CONCLUSION: Our results suggest that specific preoperative education of patients using PCA does not alter pain scores, morphine consumption or patient satisfaction but may result in earlier and more effective use of anti-emetic medication.

Gastroesophageal reflux and tracheal contamination during laparoscopic cholecystectomy and diagnostic gynecological laparoscopy.

UNLABELLED: Laparoscopy causes an increase in intraabdominal pressure and may lead to an increase in gastroesophageal reflux (GER). We designed this study to assess and compare the frequency of GER and tracheal contamination in patients undergoing laparoscopic cholecystectomy (LC) and gynecological laparoscopy (LG). We studied 20 LC and 17 LG patients. The pH was measured using monocrystalline antimony pH electrodes positioned in the middle to upper esophagus and on the posterior wall of the trachea distal to the tip of the endotracheal tube. Acid reflux was defined as a decrease in esophageal pH to 4.0 or less. Alkaline reflux was defined as an abrupt increase in esophageal pH of more than 1.0, not associated with previous acid reflux. More than 80% of all patients at baseline had a gastric pH < or = 2. Overall, acid GER alone occurred in 47% patients in the LG group and in 15% patients in the LC group. During recovery, a larger proportion of patients had acid reflux in the LG group (47%) than in the LC group (10%). In contrast, alkaline reflux occurred in 75% of LC patients and 11.7% of LG patients. After cholecystectomy, there is an acute increase in the incidence of alkaline reflux. This alkaline reflux may be due to duodenogastric reflux resulting in an alkaline gastric shift. IMPLICATIONS: We studied the incidence of reflux of stomach contents in patients undergoing laparoscopic (keyhole) surgery for cholecystectomy or gynecology, using pH probes in the esophagus (gullet) and the trachea (windpipe). Acid reflux was very common but did not pass into the trachea. After gallbladder removal, the refluxed material became alkaline.

Sol-gel based amperometric biosensor incorporating an osmium redox polymer as mediator for detection of L-lactate.

A novel amperometric biosensor for the determination of lactate was constructed by first immobilizing lactate oxidase and an osmium redox polymer ([Os(bpy)(2)(PVP)(10)Cl]Cl; abbreviated Os-polymer) on the surface of a glassy carbon electrode, followed by coating with a sol-gel film derived from methyltriethoxysilane (MTEOS). The electrooxidation current of this electrode was found to be diffusion controlled. In the presence of lactate, a clear electrocatalytic oxidation wave was observed, and lactate could be determined amperometrically at 400 mV versus Ag AgCl . The concentration range of linear response, slope of linear response and detection limit were 0.1-9 mM, 1.02 microA mM(-1), and 0.05 mM, respectively. Although L-ascorbate was electrooxidized at this potential, uric acid, paracetamol and glucose were found not to interfere.

Novel instrumentation for real-time monitoring using miniaturized flow systems with integrated biosensors.

A prototype miniaturized Total Chemical Analysis System (muTAS) has been developed and applied to on-line monitoring of glucose and lactate in the core blood of anaesthetized dogs. The system consists of a highly efficient microdialysis sampling interface sited in a small-scale extracorporeal shunt circuit ('MiniShunt'), a silicon machined microflow manifold and integrated biosensor array for glucose and lactate detection with associated computer software for analytical process control. During in-vivo testing the device allowed real-time on-screen monitoring of glucose and lactate with system response times of less than 5 min, made possible by the small dead volume of the microflow system. On-line glucose and lactate measurements were made in the basal state as well as during intravenous infusion of glucose or lactate. The prototype muTAS is currently suitable for trend monitoring but refinements are necessary before application of the system for determination of individual lactate values.

In vitro optimisation of a microdialysis system with potential for on-line monitoring of lactate and glucose in biological samples.

The optimisation and evaluation of the microdialysis component of a prototype miniaturised total analysis system for application in the continuous monitoring of lactate and glucose is reported. The complete unit comprises a high efficiency microdialysis sampling system, a miniaturised microflow manifold with an integrated biosensor array, together with the hardware and software necessary for controlling the flow parameters and monitoring the sensor signals. Sampling occurs via a microdialysis shunt probe which is perfused continuously with a physiological buffered saline solution. The continuous dialysate outflow is presented to the biosensor array, resulting in the appropriate amperometric signals. Aspects of technological significance addressed here include probe membrane size, perfusate flow rate, sample flow rate, temperature change, probe sterilisation procedures, and heparin content of the physiological saline solution employed.

An intravascular microdialysis sampling system suitable for application in continuous biochemical monitoring of glucose and lactate.

Direct sensor implantation for continuous biochemical monitoring has proved disappointing, but microdialysis sampling devices can serve as a biocompatible patient-sensor interface. We propose a novel "MiniShunt" extracorporeal microdialysis sampling circuit designed to sample core blood, and report the performance of different microdialysis probe membrane types and sizes with pumped and non-pumped blood flow in anaesthetised dogs. Discrete microdialysate and plasma samples collected during glucose and lactate monitoring were analysed with a YSI analyzer and showed microdialysis efficiency (% relative recovery) in excess of 95% for both analytes using fibres of greater than 70 mm2 internal surface area. Pumped veno-venous extracorporeal blood microdialysis sampling of this type could provide a suitable interface for future multi-analyte on-line biosensor applications in critically ill patients.

The incidence of gastroesophageal reflux with the laryngeal mask: a comparison with the face mask using esophageal lumen pH electrodes.

To test the hypothesis that the laryngeal mask airway (LMA) predisposes patients to gastroesophageal reflux, we randomly assigned 55 patients having elective surgery to receive standardized anesthesia with the LMA or with conventional face mask (FM) plus airway. A pH-sensitive probe with two electrodes, 10 cm apart, was passed nasally into the esophagus 1 h before induction of anesthesia, and recordings were made continuously until 30 min after surgery. At the distal electrode, 30 cm from the anterior nares, there was a significant difference in the incidence of reflux: 53.6% with the LMA versus 22.2% with the FM (P < 0.05). At the level of the proximal electrode, 20 cm from the anterior nares, there was no difference between groups. Multiple reflux events, defined as two or more reflux events before, during, or after anesthesia, were significantly more frequent in the LMA group (P < 0.05). Reflux events continued in the postanesthesia care unit (PACU) in both groups with no significant difference between groups. There was no clinical evidence of aspiration of gastric contents in either group. Use of the LMA appears to result in increased reflux to the level of the mid to upper esophagus, and is associated with a more frequent incidence of multiple reflux events than use of the FM.

Hypomagnesemia in continuous ambulatory peritoneal dialysis patients dialyzed with a low-magnesium peritoneal dialysis solution.

OBJECTIVE: Previous studies have shown a decrease in serum magnesium (Mg) concentration when continuous ambulatory peritoneal dialysis (CAPD) patients previously maintained on a 1.0-1.2 mEq/L Mg peritoneal dialysis solution (PDS) were dialyzed with a 0.5 mEq/L Mg PDS. However, the prevalence of hypomagnesemia in CAPD patients dialyzed with low-Mg PDS is unknown. DESIGN: A retrospective study to determine the prevalence of hypomagnesemia and the factors associated with its occurrence in CAPD patients dialyzed using a 0.5 mEq/L Mg PDS. SETTING: A CAPD unit in a large Veterans Affairs Hospital. PATIENTS: All our CAPD patients (33) enrolled over a 52-month period. RESULTS: All patients had serum magnesium levels higher than 1.25 mEq/L prior to use of low-Mg PDS. Hypomagnesemia (serum Mg < 1.25 mEq/L) developed in 21/33 patients (64%) when a 0.5 mEq/L Mg PDS was employed. Hypomagnesemia developed a mean of 8.2 months after beginning treatments. The duration of dialysis and the number of episodes of peritonitis did not differ between patients with and those without hypomagnesemia. Serum albumin levels were significantly lower in patients with hypomagnesemia (2.5 +/- 0.12 g/dL vs 3.2 +/- 0.12, p < 0.01). Magnesium supplements were given to 13 patients; following this therapy, serum magnesium values became normal. CONCLUSIONS: CAPD patients dialyzed with a 0.5 mEq/L Mg PDS may develop a considerable fall in serum magnesium level and may require magnesium supplements in order to restore normal serum values.

Continuous ambulatory peritoneal dialysis using self-made, ultrafiltration-sterilized, L-lactate-based dialysis solution.

Continuous ambulatory peritoneal dialysis was successfully carried out in 6 end-stage renal failure patients using self-made, ultrafiltration-sterilized dialysis solutions. A Y-set was used to deliver the above solutions to sterile plastic bags.

Cerebellar ataxia and ectodermal dysplasia in brothers.

Two brothers are documented with an ectodermal dysplasia primarily involving the teeth and hair. Both have developed cerebellar ataxia in the early teens.

Peritoneal dialysis using conventional, lactate--containing solution sterilized by ultrafiltration.

Peritoneal dialysis was performed on 7 end-stage renal failure patients using an I-lactate-containing solution sterilized by ultrafiltration through polyamide filters. The patients tolerated the procedure well while their metabolic acidosis and azotemia improved.

Peritoneal dialysis using bicarbonate-containing solution sterilized by ultrafiltration.

We performed acute peritoneal dialysis on eight end-stage renal disease patients using a bicarbonate-containing solution sterilized by ultrafiltration through polyamide filters. The patients tolerated the procedure well; their azotemia and metabolic acidosis improved.